High-intensity physical activity is not associated with better cognition in the elder: evidence from the China Health and Retirement Longitudinal Study

Background To evaluate the association of physical activity (PA) intensity with cognitive performance at baseline and during follow-up. Methods A total of 4039 participants aged 45 years or above from the China Health and Retirement Longitudinal Study were enrolled in visit 1 (2011-2012) and followed for cognitive function in visit 2 (2013-2014), visit 3 (2015-2016), and visit 4 (2017-2018). We analyzed the association of PA intensity with global cognition, episodic memory, and mental intactness at baseline using adjusted regression methods and evaluated the long-term effect of PA intensity using multiple measures of cognition scores by mixed effect model. Results In cross-sectional analysis, mild and moderate PA, rather than vigorous PA, was associated with better cognitive performance. The results remained consistent in multiple sensitivity analyses. During the follow-up, participant with mild PA had a 0.56 (95% CI 0.12-0.99) higher global cognition, 0.23 (95% CI 0.01-0.46) higher episodic memory, and 0.33 (95% CI 0.01-0.64) higher mental intactness, while those with moderate PA had a 0.74 (95% CI 0.32-1.17) higher global score, 0.32 (95% CI 0.09-0.54) higher episodic memory, and 0.43 (95% CI 0.12-0.74) higher mental intactness, compared with individuals without PA. Vigorous PA was not beneficial to the long-term cognitive performance. Conclusions Our study indicates that mild and moderate PA could improve cognitive performance, rather than the vigorous activity. The targeted intensity of PA might be more effective to achieve the greatest cognition improvement considering age and depressive status.